Landslide-Induced Tsunamis of Southern Alaska
Working with partners to study and inform the Nation about geohazard risks
One example of how the CMHRP works with partners to study and inform the Nation about geohazard risks is the collaborative research conducted with colleagues from Boise State University and the Alaska Department of Fish and Game on the links between earthquakes, submarine landslides, and tsunamis across southern Alaska. The Great Alaska Earthquake of 1964 (magnitude 9.2) was associated with a destructive tsunami that affected a wide swath of southern Alaska’s coastline both during and immediately following the earthquake. This event generated two types of ocean waves. Sudden crustal movement that caused the earthquake produced long-period ocean waves that propagated across the Pacific Ocean as far as Antarctica. Shorter period ocean waves were generated locally within the enclosed fjords and straits of southern Alaska and were related to offshore landslides. These shorter period waves had catastrophic effects on the coastal communities of Valdez, Seward, and Whittier.
The CMHRP is mapping and dating submarine landslide deposits in this area to determine how frequently earthquakes occurred in the past in order to infer when they might happen in the future. For the 1964 earthquake, observations on land indicate how high the ocean water levels rose during the tsunami, and models provide insight about seismic wave patterns. This information, coupled with new offshore geophysical data that constrain landslide distribution, geometry, and size, support reconstruction of prehistoric events as well as coastal risk assessments related to future submarine slides.
Learn more about the CMHRP Decadal Strategic Plan, and visit the Geohazards Project page
The CMHRP Decadal Science Strategy 2020-2030
This geonarrative constitutes the Decadal Science Strategy of the USGS's Coastal and Marine Hazards and Resources Program for 2020 to 2030.
Coastal and Marine Geohazards of the U.S. West Coast and Alaska
Working with partners to study and inform the Nation about geohazard risks
One example of how the CMHRP works with partners to study and inform the Nation about geohazard risks is the collaborative research conducted with colleagues from Boise State University and the Alaska Department of Fish and Game on the links between earthquakes, submarine landslides, and tsunamis across southern Alaska. The Great Alaska Earthquake of 1964 (magnitude 9.2) was associated with a destructive tsunami that affected a wide swath of southern Alaska’s coastline both during and immediately following the earthquake. This event generated two types of ocean waves. Sudden crustal movement that caused the earthquake produced long-period ocean waves that propagated across the Pacific Ocean as far as Antarctica. Shorter period ocean waves were generated locally within the enclosed fjords and straits of southern Alaska and were related to offshore landslides. These shorter period waves had catastrophic effects on the coastal communities of Valdez, Seward, and Whittier.
The CMHRP is mapping and dating submarine landslide deposits in this area to determine how frequently earthquakes occurred in the past in order to infer when they might happen in the future. For the 1964 earthquake, observations on land indicate how high the ocean water levels rose during the tsunami, and models provide insight about seismic wave patterns. This information, coupled with new offshore geophysical data that constrain landslide distribution, geometry, and size, support reconstruction of prehistoric events as well as coastal risk assessments related to future submarine slides.
Learn more about the CMHRP Decadal Strategic Plan, and visit the Geohazards Project page
The CMHRP Decadal Science Strategy 2020-2030
This geonarrative constitutes the Decadal Science Strategy of the USGS's Coastal and Marine Hazards and Resources Program for 2020 to 2030.